Heat pipe



FIG. 1 is a front elevational view of a preferred embodiment of a newdesign for the heat pipe, the rear elevational view being identicalthereto, and the portion of the heat pipe depicted in broken lines beingno part of the design;

FIG. 2 is a top plan view of FIG. 1, and the bottom view being identicalthereto;

FIG. 3 is a left end view of FIG. 1; and,

FIG. 4 is a right end view of FIG. 1.

The ornamental design for the heat pipe, as shown and decribed.